Old beast I noticed that could be heard on the way (9)
I believe the answer is:
stegosaur
'old beast' is the definition.
(I've seen this before)
'i noticed that could be heard on the way' is the wordplay.
I cannot quite see how this works, but
'i' could be 'ego' (I've seen this before) and 'ego' is found in the answer.
'way' could be 'st' and 'st' is located in the answer.
This explanation may well be incorrect...
(Other definitions for stegosaur that I've seen before include "old dinosaur" , "Jurassic creature" , "Armoured fossil creature" , "Old beast" , "prehistoric creature" .)